Probably irrelevant but there was a software tweak:
"Fixed an issue with MFDs unable to configure the GFL10 Tank Capacity."
I know you don't have a GFL10 but it might do something to yours?
Ver 5.9 onwards, don't know how old, you may well be ahead of that already
Also, I haven't got it with me but my new smartcraft manual goes into a fair bit of detail on tank calibration. I did have a quick read and it didn't sound that straightforward. As my 5012 is now showing a page full of fuel data same as yours, it may offer an insight